HscMain.hs 64 KB
Newer Older
dterei's avatar
dterei committed
1 2
-------------------------------------------------------------------------------
--
3
-- | Main API for compiling plain Haskell source code.
4
--
dterei's avatar
dterei committed
5
-- This module implements compilation of a Haskell source. It is
6 7 8 9 10
-- /not/ concerned with preprocessing of source files; this is handled
-- in "DriverPipeline".
--
-- There are various entry points depending on what mode we're in:
-- "batch" mode (@--make@), "one-shot" mode (@-c@, @-S@ etc.), and
dterei's avatar
dterei committed
11
-- "interactive" mode (GHCi). There are also entry points for
12 13 14 15 16 17 18 19 20 21 22 23
-- individual passes: parsing, typechecking/renaming, desugaring, and
-- simplification.
--
-- All the functions here take an 'HscEnv' as a parameter, but none of
-- them return a new one: 'HscEnv' is treated as an immutable value
-- from here on in (although it has mutable components, for the
-- caches).
--
-- Warning messages are dealt with consistently throughout this API:
-- during compilation warnings are collected, and before any function
-- in @HscMain@ returns, the warnings are either printed, or turned
-- into a real compialtion error if the @-Werror@ flag is enabled.
24
--
dterei's avatar
dterei committed
25 26 27 28
-- (c) The GRASP/AQUA Project, Glasgow University, 1993-2000
--
-------------------------------------------------------------------------------

29
module HscMain
dterei's avatar
dterei committed
30
    (
31 32 33 34 35
    -- * Making an HscEnv
      newHscEnv

    -- * Compiling complete source files
    , Compiler
Thomas Schilling's avatar
Thomas Schilling committed
36
    , HscStatus' (..)
37
    , InteractiveStatus, HscStatus
38 39 40 41 42 43 44 45
    , hscCompileOneShot
    , hscCompileBatch
    , hscCompileNothing
    , hscCompileInteractive
    , hscCompileCmmFile
    , hscCompileCore

    -- * Running passes separately
Thomas Schilling's avatar
Thomas Schilling committed
46 47 48
    , hscParse
    , hscTypecheckRename
    , hscDesugar
Simon Marlow's avatar
Simon Marlow committed
49 50
    , makeSimpleIface
    , makeSimpleDetails
51 52 53 54 55 56 57 58 59 60 61 62 63
    , hscSimplify -- ToDo, shouldn't really export this

    -- ** Backends
    , hscOneShotBackendOnly
    , hscBatchBackendOnly
    , hscNothingBackendOnly
    , hscInteractiveBackendOnly

    -- * Support for interactive evaluation
    , hscParseIdentifier
    , hscTcRcLookupName
    , hscTcRnGetInfo
#ifdef GHCI
64
    , hscGetModuleInterface
65
    , hscRnImportDecls
66
    , hscTcRnLookupRdrName
vivian's avatar
vivian committed
67
    , hscStmt, hscStmtWithLocation
68
    , hscDecls, hscDeclsWithLocation
vivian's avatar
vivian committed
69
    , hscTcExpr, hscImport, hscKcType
70 71
    , hscCompileCoreExpr
#endif
72
    ) where
73

74
#ifdef GHCI
75
import ByteCodeGen      ( byteCodeGen, coreExprToBCOs )
76
import Linker
77 78
import CoreTidy         ( tidyExpr )
import Type             ( Type )
79
import PrelNames
80 81 82
import {- Kind parts of -} Type         ( Kind )
import CoreLint         ( lintUnfolding )
import DsMeta           ( templateHaskellNames )
83
import VarSet
84
import VarEnv           ( emptyTidyEnv )
simonpj@microsoft.com's avatar
simonpj@microsoft.com committed
85
import Panic
86 87
#endif

88
import Id
89 90
import Module
import Packages
Simon Marlow's avatar
Simon Marlow committed
91 92
import RdrName
import HsSyn
93
import CoreSyn
Ian Lynagh's avatar
Ian Lynagh committed
94
import StringBuffer
95
import Parser
96 97 98
import Lexer hiding (getDynFlags)
import SrcLoc
import TcRnDriver
99
import TcIface          ( typecheckIface )
100
import TcRnMonad
101 102
import IfaceEnv         ( initNameCache )
import LoadIface        ( ifaceStats, initExternalPackageState )
103
import PrelInfo
Simon Marlow's avatar
Simon Marlow committed
104
import MkIface
105 106
import Desugar
import SimplCore
Simon Marlow's avatar
Simon Marlow committed
107
import TidyPgm
108
import CorePrep
109 110
import CoreToStg        ( coreToStg )
import qualified StgCmm ( codeGen )
111 112
import StgSyn
import CostCentre
113
import ProfInit
114 115
import TyCon
import Name
116 117
import SimplStg         ( stg2stg )
import CodeGen          ( codeGen )
Simon Peyton Jones's avatar
Simon Peyton Jones committed
118
import OldCmm as Old    ( CmmGroup )
119 120
import PprCmm           ( pprCmms )
import CmmParse         ( parseCmmFile )
121
import CmmBuildInfoTables
Edward Z. Yang's avatar
Edward Z. Yang committed
122
import CmmPipeline
123
import CmmInfo
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
124
import OptimizationFuel ( initOptFuelState )
125
import CmmCvt
126
import CodeOutput
127
import NameEnv          ( emptyNameEnv )
128 129
import NameSet          ( emptyNameSet )
import InstEnv
130
import FamInstEnv
Thomas Schilling's avatar
Thomas Schilling committed
131
import Fingerprint      ( Fingerprint )
132

133
import DynFlags
134
import ErrUtils
135
import UniqSupply       ( mkSplitUniqSupply )
136

137
import Outputable
138
import HscStats         ( ppSourceStats )
139
import HscTypes
140
import MkExternalCore   ( emitExternalCore )
141
import FastString
142
import UniqFM           ( emptyUFM )
143
import UniqSupply       ( initUs_ )
144
import Bag
Thomas Schilling's avatar
Thomas Schilling committed
145
import Exception
Simon Marlow's avatar
Simon Marlow committed
146

147
import Data.List
Simon Marlow's avatar
Simon Marlow committed
148
import Control.Monad
149
import Data.Maybe
Simon Marlow's avatar
Simon Marlow committed
150
import Data.IORef
151
import System.FilePath as FilePath
dterei's avatar
dterei committed
152

Thomas Schilling's avatar
Thomas Schilling committed
153
#include "HsVersions.h"
154

155

dterei's avatar
dterei committed
156 157 158 159 160
{- **********************************************************************
%*                                                                      *
                Initialisation
%*                                                                      *
%********************************************************************* -}
161

162
newHscEnv :: DynFlags -> IO HscEnv
163
newHscEnv dflags = do
dterei's avatar
dterei committed
164 165 166 167 168 169 170
    eps_var <- newIORef initExternalPackageState
    us      <- mkSplitUniqSupply 'r'
    nc_var  <- newIORef (initNameCache us knownKeyNames)
    fc_var  <- newIORef emptyUFM
    mlc_var <- newIORef emptyModuleEnv
    optFuel <- initOptFuelState
    safe_var <- newIORef True
171
    return HscEnv {  hsc_dflags       = dflags,
dterei's avatar
dterei committed
172 173 174 175 176 177 178 179 180
                     hsc_targets      = [],
                     hsc_mod_graph    = [],
                     hsc_IC           = emptyInteractiveContext,
                     hsc_HPT          = emptyHomePackageTable,
                     hsc_EPS          = eps_var,
                     hsc_NC           = nc_var,
                     hsc_FC           = fc_var,
                     hsc_MLC          = mlc_var,
                     hsc_OptFuel      = optFuel,
dterei's avatar
dterei committed
181
                     hsc_type_env_var = Nothing,
dterei's avatar
dterei committed
182
                     hsc_safeInf      = safe_var }
Thomas Schilling's avatar
Thomas Schilling committed
183

184

185
knownKeyNames :: [Name]      -- Put here to avoid loops involving DsMeta,
186
knownKeyNames =              -- where templateHaskellNames are defined
dterei's avatar
dterei committed
187
    map getName wiredInThings
dterei's avatar
dterei committed
188
        ++ basicKnownKeyNames
189
#ifdef GHCI
dterei's avatar
dterei committed
190
        ++ templateHaskellNames
191 192
#endif

193
-- -----------------------------------------------------------------------------
194
-- The Hsc monad: Passing an enviornment and warning state
195

dterei's avatar
dterei committed
196
newtype Hsc a = Hsc (HscEnv -> WarningMessages -> IO (a, WarningMessages))
197 198

instance Monad Hsc where
dterei's avatar
dterei committed
199 200 201 202
    return a    = Hsc $ \_ w -> return (a, w)
    Hsc m >>= k = Hsc $ \e w -> do (a, w1) <- m e w
                                   case k a of
                                       Hsc k' -> k' e w1
203 204

instance MonadIO Hsc where
dterei's avatar
dterei committed
205
    liftIO io = Hsc $ \_ w -> do a <- io; return (a, w)
206 207 208

runHsc :: HscEnv -> Hsc a -> IO a
runHsc hsc_env (Hsc hsc) = do
dterei's avatar
dterei committed
209 210 211
    (a, w) <- hsc hsc_env emptyBag
    printOrThrowWarnings (hsc_dflags hsc_env) w
    return a
212 213

getWarnings :: Hsc WarningMessages
dterei's avatar
dterei committed
214
getWarnings = Hsc $ \_ w -> return (w, w)
215 216

clearWarnings :: Hsc ()
dterei's avatar
dterei committed
217
clearWarnings = Hsc $ \_ _ -> return ((), emptyBag)
218 219

logWarnings :: WarningMessages -> Hsc ()
dterei's avatar
dterei committed
220
logWarnings w = Hsc $ \_ w0 -> return ((), w0 `unionBags` w)
221 222

getHscEnv :: Hsc HscEnv
dterei's avatar
dterei committed
223
getHscEnv = Hsc $ \e w -> return (e, w)
224 225

getDynFlags :: Hsc DynFlags
dterei's avatar
dterei committed
226
getDynFlags = Hsc $ \e w -> return (hsc_dflags e, w)
227 228 229

handleWarnings :: Hsc ()
handleWarnings = do
dterei's avatar
dterei committed
230 231 232 233
    dflags <- getDynFlags
    w <- getWarnings
    liftIO $ printOrThrowWarnings dflags w
    clearWarnings
234 235 236 237 238

-- | log warning in the monad, and if there are errors then
-- throw a SourceError exception.
logWarningsReportErrors :: Messages -> Hsc ()
logWarningsReportErrors (warns,errs) = do
dterei's avatar
dterei committed
239 240
    logWarnings warns
    when (not $ isEmptyBag errs) $ throwErrors errs
241 242 243 244

-- | Throw some errors.
throwErrors :: ErrorMessages -> Hsc a
throwErrors = liftIO . throwIO . mkSrcErr
245 246 247 248 249

-- | Deal with errors and warnings returned by a compilation step
--
-- In order to reduce dependencies to other parts of the compiler, functions
-- outside the "main" parts of GHC return warnings and errors as a parameter
dterei's avatar
dterei committed
250
-- and signal success via by wrapping the result in a 'Maybe' type. This
251 252 253 254 255 256 257 258 259
-- function logs the returned warnings and propagates errors as exceptions
-- (of type 'SourceError').
--
-- This function assumes the following invariants:
--
--  1. If the second result indicates success (is of the form 'Just x'),
--     there must be no error messages in the first result.
--
--  2. If there are no error messages, but the second result indicates failure
dterei's avatar
dterei committed
260
--     there should be warnings in the first result. That is, if the action
261 262 263
--     failed, it must have been due to the warnings (i.e., @-Werror@).
ioMsgMaybe :: IO (Messages, Maybe a) -> Hsc a
ioMsgMaybe ioA = do
dterei's avatar
dterei committed
264 265 266 267 268
    ((warns,errs), mb_r) <- liftIO $ ioA
    logWarnings warns
    case mb_r of
        Nothing -> throwErrors errs
        Just r  -> ASSERT( isEmptyBag errs ) return r
269 270 271 272 273

-- | like ioMsgMaybe, except that we ignore error messages and return
-- 'Nothing' instead.
ioMsgMaybe' :: IO (Messages, Maybe a) -> Hsc (Maybe a)
ioMsgMaybe' ioA = do
dterei's avatar
dterei committed
274 275 276
    ((warns,_errs), mb_r) <- liftIO $ ioA
    logWarnings warns
    return mb_r
277 278 279 280 281 282

-- -----------------------------------------------------------------------------
-- | Lookup things in the compiler's environment

#ifdef GHCI
hscTcRnLookupRdrName :: HscEnv -> RdrName -> IO [Name]
dterei's avatar
dterei committed
283
hscTcRnLookupRdrName hsc_env rdr_name =
dterei's avatar
dterei committed
284
    runHsc hsc_env $ ioMsgMaybe $ tcRnLookupRdrName hsc_env rdr_name
285 286 287
#endif

hscTcRcLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
dterei's avatar
dterei committed
288
hscTcRcLookupName hsc_env name =
dterei's avatar
dterei committed
289 290 291 292
    runHsc hsc_env $ ioMsgMaybe' $ tcRnLookupName hsc_env name
      -- ignore errors: the only error we're likely to get is
      -- "name not found", and the Maybe in the return type
      -- is used to indicate that.
293 294 295

hscTcRnGetInfo :: HscEnv -> Name -> IO (Maybe (TyThing, Fixity, [Instance]))
hscTcRnGetInfo hsc_env name =
dterei's avatar
dterei committed
296
    runHsc hsc_env $ ioMsgMaybe' $ tcRnGetInfo hsc_env name
297 298

#ifdef GHCI
299
hscGetModuleInterface :: HscEnv -> Module -> IO ModIface
300
hscGetModuleInterface hsc_env mod =
dterei's avatar
dterei committed
301
    runHsc hsc_env $ ioMsgMaybe $ getModuleInterface hsc_env mod
302 303 304

-- -----------------------------------------------------------------------------
-- | Rename some import declarations
305
hscRnImportDecls :: HscEnv -> [LImportDecl RdrName] -> IO GlobalRdrEnv
dterei's avatar
dterei committed
306 307
hscRnImportDecls hsc_env import_decls =
    runHsc hsc_env $ ioMsgMaybe $ tcRnImportDecls hsc_env import_decls
308 309
#endif

310
-- -----------------------------------------------------------------------------
Simon Marlow's avatar
Simon Marlow committed
311
-- | parse a file, returning the abstract syntax
312

313
hscParse :: HscEnv -> ModSummary -> IO HsParsedModule
314 315 316
hscParse hsc_env mod_summary = runHsc hsc_env $ hscParse' mod_summary

-- internal version, that doesn't fail due to -Werror
317
hscParse' :: ModSummary -> Hsc HsParsedModule
318
hscParse' mod_summary = do
dterei's avatar
dterei committed
319 320 321
    dflags <- getDynFlags
    let src_filename  = ms_hspp_file mod_summary
        maybe_src_buf = ms_hspp_buf  mod_summary
322

dterei's avatar
dterei committed
323 324 325
    --------------------------  Parser  ----------------
    liftIO $ showPass dflags "Parser"
    {-# SCC "Parser" #-} do
326 327 328 329

    -- sometimes we already have the buffer in memory, perhaps
    -- because we needed to parse the imports out of it, or get the
    -- module name.
dterei's avatar
dterei committed
330 331 332
    buf <- case maybe_src_buf of
               Just b  -> return b
               Nothing -> liftIO $ hGetStringBuffer src_filename
333

dterei's avatar
dterei committed
334
    let loc = mkRealSrcLoc (mkFastString src_filename) 1 1
335

dterei's avatar
dterei committed
336 337 338
    case unP parseModule (mkPState dflags buf loc) of
        PFailed span err ->
            liftIO $ throwOneError (mkPlainErrMsg span err)
339

dterei's avatar
dterei committed
340 341 342 343 344 345
        POk pst rdr_module -> do
            logWarningsReportErrors (getMessages pst)
            liftIO $ dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" $
                                   ppr rdr_module
            liftIO $ dumpIfSet_dyn dflags Opt_D_source_stats "Source Statistics" $
                                   ppSourceStats False rdr_module
346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371

            -- To get the list of extra source files, we take the list
            -- that the parser gave us,
            --   - eliminate files beginning with '<'.  gcc likes to use
            --     pseudo-filenames like "<built-in>" and "<command-line>"
            --   - normalise them (elimiante differences between ./f and f)
            --   - filter out the preprocessed source file
            --   - filter out anything beginning with tmpdir
            --   - remove duplicates
            --   - filter out the .hs/.lhs source filename if we have one
            --
            let n_hspp  = FilePath.normalise src_filename
                srcs0 = nub $ filter (not . (tmpDir dflags `isPrefixOf`))
                            $ filter (not . (== n_hspp))
                            $ map FilePath.normalise
                            $ filter (not . (== '<') . head)
                            $ map unpackFS
                            $ srcfiles pst
                srcs1 = case ml_hs_file (ms_location mod_summary) of
                          Just f  -> filter (/= FilePath.normalise f) srcs0
                          Nothing -> srcs0

            return HsParsedModule {
                      hpm_module    = rdr_module,
                      hpm_src_files = srcs1
                   }
Simon Marlow's avatar
Simon Marlow committed
372

Thomas Schilling's avatar
Thomas Schilling committed
373 374 375
-- XXX: should this really be a Maybe X?  Check under which circumstances this
-- can become a Nothing and decide whether this should instead throw an
-- exception/signal an error.
dterei's avatar
dterei committed
376
type RenamedStuff =
Simon Marlow's avatar
Simon Marlow committed
377
        (Maybe (HsGroup Name, [LImportDecl Name], Maybe [LIE Name],
378
                Maybe LHsDocString))
Simon Marlow's avatar
Simon Marlow committed
379

Thomas Schilling's avatar
Thomas Schilling committed
380
-- | Rename and typecheck a module, additionally returning the renamed syntax
381
hscTypecheckRename :: HscEnv -> ModSummary -> HsParsedModule
382
                   -> IO (TcGblEnv, RenamedStuff)
dterei's avatar
dterei committed
383
hscTypecheckRename hsc_env mod_summary rdr_module = runHsc hsc_env $ do
384
    tc_result <- {-# SCC "Typecheck-Rename" #-}
dterei's avatar
dterei committed
385
                 ioMsgMaybe $
dterei's avatar
dterei committed
386 387
                     tcRnModule hsc_env (ms_hsc_src mod_summary)
                                True rdr_module
Thomas Schilling's avatar
Thomas Schilling committed
388

389 390 391 392 393 394
        -- This 'do' is in the Maybe monad!
    let rn_info = do decl <- tcg_rn_decls tc_result
                     let imports = tcg_rn_imports tc_result
                         exports = tcg_rn_exports tc_result
                         doc_hdr = tcg_doc_hdr tc_result
                     return (decl,imports,exports,doc_hdr)
Thomas Schilling's avatar
Thomas Schilling committed
395

396
    return (tc_result, rn_info)
Simon Marlow's avatar
Simon Marlow committed
397 398

-- | Convert a typechecked module to Core
399
hscDesugar :: HscEnv -> ModSummary -> TcGblEnv -> IO ModGuts
400
hscDesugar hsc_env mod_summary tc_result =
dterei's avatar
dterei committed
401
    runHsc hsc_env $ hscDesugar' mod_summary tc_result
402 403

hscDesugar' :: ModSummary -> TcGblEnv -> Hsc ModGuts
404
hscDesugar' mod_summary tc_result = do
dterei's avatar
dterei committed
405
    hsc_env <- getHscEnv
Simon Marlow's avatar
Simon Marlow committed
406 407 408
    r <- ioMsgMaybe $
      {-# SCC "deSugar" #-}
      deSugar hsc_env (ms_location mod_summary) tc_result
409

dterei's avatar
dterei committed
410 411 412 413
    -- always check -Werror after desugaring, this is the last opportunity for
    -- warnings to arise before the backend.
    handleWarnings
    return r
Simon Marlow's avatar
Simon Marlow committed
414

dterei's avatar
dterei committed
415
-- | Make a 'ModIface' from the results of typechecking. Used when
Simon Marlow's avatar
Simon Marlow committed
416 417 418 419
-- not optimising, and the interface doesn't need to contain any
-- unfoldings or other cross-module optimisation info.
-- ToDo: the old interface is only needed to get the version numbers,
-- we should use fingerprint versions instead.
420
makeSimpleIface :: HscEnv -> Maybe ModIface -> TcGblEnv -> ModDetails
421
                -> IO (ModIface,Bool)
422
makeSimpleIface hsc_env maybe_old_iface tc_result details =
dterei's avatar
dterei committed
423
    runHsc hsc_env $ ioMsgMaybe $
dterei's avatar
dterei committed
424
        mkIfaceTc hsc_env (fmap mi_iface_hash maybe_old_iface) details tc_result
Simon Marlow's avatar
Simon Marlow committed
425

dterei's avatar
dterei committed
426
-- | Make a 'ModDetails' from the results of typechecking. Used when
Simon Marlow's avatar
Simon Marlow committed
427
-- typechecking only, as opposed to full compilation.
428 429
makeSimpleDetails :: HscEnv -> TcGblEnv -> IO ModDetails
makeSimpleDetails hsc_env tc_result = mkBootModDetailsTc hsc_env tc_result
Simon Marlow's avatar
Simon Marlow committed
430

431

dterei's avatar
dterei committed
432 433 434 435 436 437 438
{- **********************************************************************
%*                                                                      *
                The main compiler pipeline
%*                                                                      *
%********************************************************************* -}

{-
439 440 441 442
                   --------------------------------
                        The compilation proper
                   --------------------------------

dterei's avatar
dterei committed
443 444 445 446 447 448
It's the task of the compilation proper to compile Haskell, hs-boot and core
files to either byte-code, hard-code (C, asm, LLVM, ect) or to nothing at all
(the module is still parsed and type-checked. This feature is mostly used by
IDE's and the likes). Compilation can happen in either 'one-shot', 'batch',
'nothing', or 'interactive' mode. 'One-shot' mode targets hard-code, 'batch'
mode targets hard-code, 'nothing' mode targets nothing and 'interactive' mode
449
targets byte-code.
dterei's avatar
dterei committed
450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475

The modes are kept separate because of their different types and meanings:

 * In 'one-shot' mode, we're only compiling a single file and can therefore
 discard the new ModIface and ModDetails. This is also the reason it only
 targets hard-code; compiling to byte-code or nothing doesn't make sense when
 we discard the result.

 * 'Batch' mode is like 'one-shot' except that we keep the resulting ModIface
 and ModDetails. 'Batch' mode doesn't target byte-code since that require us to
 return the newly compiled byte-code.

 * 'Nothing' mode has exactly the same type as 'batch' mode but they're still
 kept separate. This is because compiling to nothing is fairly special: We
 don't output any interface files, we don't run the simplifier and we don't
 generate any code.

 * 'Interactive' mode is similar to 'batch' mode except that we return the
 compiled byte-code together with the ModIface and ModDetails.

Trying to compile a hs-boot file to byte-code will result in a run-time error.
This is the only thing that isn't caught by the type-system.
-}


-- | Status of a compilation to hard-code or nothing.
Thomas Schilling's avatar
Thomas Schilling committed
476
data HscStatus' a
477
    = HscNoRecomp
Thomas Schilling's avatar
Thomas Schilling committed
478
    | HscRecomp
dterei's avatar
dterei committed
479 480 481 482 483
          (Maybe FilePath) -- Has stub files. This is a hack. We can't compile
                           -- C files here since it's done in DriverPipeline.
                           -- For now we just return True if we want the caller
                           -- to compile them for us.
          a
Thomas Schilling's avatar
Thomas Schilling committed
484

dterei's avatar
dterei committed
485
-- This is a bit ugly. Since we use a typeclass below and would like to avoid
Thomas Schilling's avatar
Thomas Schilling committed
486
-- functional dependencies, we have to parameterise the typeclass over the
dterei's avatar
dterei committed
487 488
-- result type. Therefore we need to artificially distinguish some types. We do
-- this by adding type tags which will simply be ignored by the caller.
489
type HscStatus         = HscStatus' ()
490 491
type InteractiveStatus = HscStatus' (Maybe (CompiledByteCode, ModBreaks))
    -- INVARIANT: result is @Nothing@ <=> input was a boot file
Thomas Schilling's avatar
Thomas Schilling committed
492

493 494 495
type OneShotResult     = HscStatus
type BatchResult       = (HscStatus, ModIface, ModDetails)
type NothingResult     = (HscStatus, ModIface, ModDetails)
Thomas Schilling's avatar
Thomas Schilling committed
496
type InteractiveResult = (InteractiveStatus, ModIface, ModDetails)
497

498 499
-- ToDo: The old interface and module index are only using in 'batch' and
--       'interactive' mode. They should be removed from 'oneshot' mode.
500
type Compiler result =  HscEnv
501
                     -> ModSummary
502
                     -> SourceModified
503 504
                     -> Maybe ModIface  -- Old interface, if available
                     -> Maybe (Int,Int) -- Just (i,n) <=> module i of n (for msgs)
505
                     -> IO result
506

dterei's avatar
dterei committed
507
data HsCompiler a = HsCompiler {
508
    -- | Called when no recompilation is necessary.
509 510
    hscNoRecomp :: ModIface
                -> Hsc a,
511 512

    -- | Called to recompile the module.
513 514
    hscRecompile :: ModSummary -> Maybe Fingerprint
                 -> Hsc a,
515

516 517
    hscBackend :: TcGblEnv -> ModSummary -> Maybe Fingerprint
               -> Hsc a,
518

519
    -- | Code generation for Boot modules.
520 521
    hscGenBootOutput :: TcGblEnv -> ModSummary -> Maybe Fingerprint
                     -> Hsc a,
522 523

    -- | Code generation for normal modules.
524 525
    hscGenOutput :: ModGuts  -> ModSummary -> Maybe Fingerprint
                 -> Hsc a
526 527
  }

528
genericHscCompile :: HsCompiler a
529 530
                  -> (HscEnv -> Maybe (Int,Int) -> RecompReason -> ModSummary -> IO ())
                  -> HscEnv -> ModSummary -> SourceModified
Thomas Schilling's avatar
Thomas Schilling committed
531
                  -> Maybe ModIface -> Maybe (Int, Int)
532 533
                  -> IO a
genericHscCompile compiler hscMessage hsc_env
534
                  mod_summary source_modified
535
                  mb_old_iface0 mb_mod_index
dterei's avatar
dterei committed
536 537 538
  = do
    (recomp_reqd, mb_checked_iface)
        <- {-# SCC "checkOldIface" #-}
dterei's avatar
dterei committed
539
           checkOldIface hsc_env mod_summary
dterei's avatar
dterei committed
540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556
                         source_modified mb_old_iface0
    -- save the interface that comes back from checkOldIface.
    -- In one-shot mode we don't have the old iface until this
    -- point, when checkOldIface reads it from the disk.
    let mb_old_hash = fmap mi_iface_hash mb_checked_iface

    let skip iface = do
            hscMessage hsc_env mb_mod_index RecompNotRequired mod_summary
            runHsc hsc_env $ hscNoRecomp compiler iface

        compile reason = do
            hscMessage hsc_env mb_mod_index reason mod_summary
            runHsc hsc_env $ hscRecompile compiler mod_summary mb_old_hash

        stable = case source_modified of
                     SourceUnmodifiedAndStable -> True
                     _                         -> False
557 558 559

        -- If the module used TH splices when it was last compiled,
        -- then the recompilation check is not accurate enough (#481)
dterei's avatar
dterei committed
560
        -- and we must ignore it. However, if the module is stable
561
        -- (none of the modules it depends on, directly or indirectly,
dterei's avatar
dterei committed
562
        -- changed), then we *can* skip recompilation. This is why
563 564 565
        -- the SourceModified type contains SourceUnmodifiedAndStable,
        -- and it's pretty important: otherwise ghc --make would
        -- always recompile TH modules, even if nothing at all has
dterei's avatar
dterei committed
566
        -- changed. Stability is just the same check that make is
567 568
        -- doing for us in one-shot mode.

dterei's avatar
dterei committed
569 570 571 572 573 574 575
    case mb_checked_iface of
        Just iface | not recomp_reqd ->
            if mi_used_th iface && not stable
                then compile RecompForcedByTH
                else skip iface
        _otherwise ->
            compile RecompRequired
Thomas Schilling's avatar
Thomas Schilling committed
576

577
hscCheckRecompBackend :: HsCompiler a -> TcGblEnv -> Compiler a
dterei's avatar
dterei committed
578 579
hscCheckRecompBackend compiler tc_result hsc_env mod_summary
                      source_modified mb_old_iface _m_of_n
580
  = do
dterei's avatar
dterei committed
581 582 583 584 585 586 587 588
    (recomp_reqd, mb_checked_iface)
        <- {-# SCC "checkOldIface" #-}
           checkOldIface hsc_env mod_summary
                         source_modified mb_old_iface

    let mb_old_hash = fmap mi_iface_hash mb_checked_iface
    case mb_checked_iface of
        Just iface | not recomp_reqd
dterei's avatar
dterei committed
589
            -> runHsc hsc_env $
dterei's avatar
dterei committed
590 591 592 593 594
                   hscNoRecomp compiler
                       iface{ mi_globals = Just (tcg_rdr_env tc_result) }
        _otherwise
            -> runHsc hsc_env $
                   hscBackend compiler tc_result mod_summary mb_old_hash
595

596
genericHscRecompile :: HsCompiler a
597
                    -> ModSummary -> Maybe Fingerprint
598
                    -> Hsc a
599
genericHscRecompile compiler mod_summary mb_old_hash
dterei's avatar
dterei committed
600 601 602 603 604
    | ExtCoreFile <- ms_hsc_src mod_summary =
        panic "GHC does not currently support reading External Core files"
    | otherwise = do
        tc_result <- hscFileFrontEnd mod_summary
        hscBackend compiler tc_result mod_summary mb_old_hash
605

606
genericHscBackend :: HsCompiler a
607
                  -> TcGblEnv -> ModSummary -> Maybe Fingerprint
608
                  -> Hsc a
609
genericHscBackend compiler tc_result mod_summary mb_old_hash
dterei's avatar
dterei committed
610 611 612 613 614
    | HsBootFile <- ms_hsc_src mod_summary =
        hscGenBootOutput compiler tc_result mod_summary mb_old_hash
    | otherwise = do
        guts <- hscDesugar' mod_summary tc_result
        hscGenOutput compiler guts mod_summary mb_old_hash
Thomas Schilling's avatar
Thomas Schilling committed
615

616 617
compilerBackend :: HsCompiler a -> TcGblEnv -> Compiler a
compilerBackend comp tcg hsc_env ms' _ _mb_old_iface _ =
dterei's avatar
dterei committed
618
    runHsc hsc_env $ hscBackend comp tcg ms' Nothing
619

620 621 622 623
--------------------------------------------------------------
-- Compilers
--------------------------------------------------------------

624
hscOneShotCompiler :: HsCompiler OneShotResult
dterei's avatar
dterei committed
625
hscOneShotCompiler = HsCompiler {
626

627
    hscNoRecomp = \_old_iface -> do
dterei's avatar
dterei committed
628 629 630
        hsc_env <- getHscEnv
        liftIO $ dumpIfaceStats hsc_env
        return HscNoRecomp
631 632 633

  , hscRecompile = genericHscRecompile hscOneShotCompiler

dterei's avatar
dterei committed
634
  , hscBackend = \tc_result mod_summary mb_old_hash -> do
dterei's avatar
dterei committed
635 636 637 638 639
        dflags <- getDynFlags
        case hscTarget dflags of
            HscNothing -> return (HscRecomp Nothing ())
            _otherw    -> genericHscBackend hscOneShotCompiler
                              tc_result mod_summary mb_old_hash
640

641
  , hscGenBootOutput = \tc_result mod_summary mb_old_iface -> do
dterei's avatar
dterei committed
642 643 644
        (iface, changed, _) <- hscSimpleIface tc_result mb_old_iface
        hscWriteIface iface changed mod_summary
        return (HscRecomp Nothing ())
645 646

  , hscGenOutput = \guts0 mod_summary mb_old_iface -> do
dterei's avatar
dterei committed
647 648 649 650 651
        guts <- hscSimplify' guts0
        (iface, changed, _details, cgguts) <- hscNormalIface guts mb_old_iface
        hscWriteIface iface changed mod_summary
        hasStub <- hscGenHardCode cgguts mod_summary
        return (HscRecomp hasStub ())
652
  }
653

Thomas Schilling's avatar
Thomas Schilling committed
654
-- Compile Haskell, boot and extCore in OneShot mode.
655
hscCompileOneShot :: Compiler OneShotResult
656 657
hscCompileOneShot hsc_env mod_summary src_changed mb_old_iface mb_i_of_n
  = do
dterei's avatar
dterei committed
658 659 660 661 662
    -- One-shot mode needs a knot-tying mutable variable for interface
    -- files. See TcRnTypes.TcGblEnv.tcg_type_env_var.
    type_env_var <- newIORef emptyNameEnv
    let mod = ms_mod mod_summary
        hsc_env' = hsc_env{ hsc_type_env_var = Just (mod, type_env_var) }
663

dterei's avatar
dterei committed
664 665 666
    genericHscCompile hscOneShotCompiler
                      oneShotMsg hsc_env' mod_summary src_changed
                      mb_old_iface mb_i_of_n
Thomas Schilling's avatar
Thomas Schilling committed
667

668 669 670
hscOneShotBackendOnly :: TcGblEnv -> Compiler OneShotResult
hscOneShotBackendOnly = compilerBackend hscOneShotCompiler

Thomas Schilling's avatar
Thomas Schilling committed
671 672
--------------------------------------------------------------

673
hscBatchCompiler :: HsCompiler BatchResult
dterei's avatar
dterei committed
674
hscBatchCompiler = HsCompiler {
Thomas Schilling's avatar
Thomas Schilling committed
675

676
    hscNoRecomp = \iface -> do
dterei's avatar
dterei committed
677 678
        details <- genModDetails iface
        return (HscNoRecomp, iface, details)
Thomas Schilling's avatar
Thomas Schilling committed
679

680
  , hscRecompile = genericHscRecompile hscBatchCompiler
Thomas Schilling's avatar
Thomas Schilling committed
681

682 683
  , hscBackend = genericHscBackend hscBatchCompiler

684
  , hscGenBootOutput = \tc_result mod_summary mb_old_iface -> do
dterei's avatar
dterei committed
685 686 687
        (iface, changed, details) <- hscSimpleIface tc_result mb_old_iface
        hscWriteIface iface changed mod_summary
        return (HscRecomp Nothing (), iface, details)
Thomas Schilling's avatar
Thomas Schilling committed
688

689
  , hscGenOutput = \guts0 mod_summary mb_old_iface -> do
dterei's avatar
dterei committed
690 691 692 693 694
        guts <- hscSimplify' guts0
        (iface, changed, details, cgguts) <- hscNormalIface guts mb_old_iface
        hscWriteIface iface changed mod_summary
        hasStub <- hscGenHardCode cgguts mod_summary
        return (HscRecomp hasStub (), iface, details)
695
  }
696

dterei's avatar
dterei committed
697
-- | Compile Haskell, boot and extCore in batch mode.
698
hscCompileBatch :: Compiler (HscStatus, ModIface, ModDetails)
699
hscCompileBatch = genericHscCompile hscBatchCompiler batchMsg
Thomas Schilling's avatar
Thomas Schilling committed
700

701 702 703
hscBatchBackendOnly :: TcGblEnv -> Compiler BatchResult
hscBatchBackendOnly = hscCheckRecompBackend hscBatchCompiler

Thomas Schilling's avatar
Thomas Schilling committed
704 705
--------------------------------------------------------------

706
hscInteractiveCompiler :: HsCompiler InteractiveResult
dterei's avatar
dterei committed
707
hscInteractiveCompiler = HsCompiler {
708
    hscNoRecomp = \iface -> do
dterei's avatar
dterei committed
709 710
        details <- genModDetails iface
        return (HscNoRecomp, iface, details)
Thomas Schilling's avatar
Thomas Schilling committed
711

712
  , hscRecompile = genericHscRecompile hscInteractiveCompiler
Thomas Schilling's avatar
Thomas Schilling committed
713

714 715 716
  , hscBackend = genericHscBackend hscInteractiveCompiler

  , hscGenBootOutput = \tc_result _mod_summary mb_old_iface -> do
dterei's avatar
dterei committed
717 718
        (iface, _changed, details) <- hscSimpleIface tc_result mb_old_iface
        return (HscRecomp Nothing Nothing, iface, details)
Thomas Schilling's avatar
Thomas Schilling committed
719

720
  , hscGenOutput = \guts0 mod_summary mb_old_iface -> do
dterei's avatar
dterei committed
721 722 723
        guts <- hscSimplify' guts0
        (iface, _changed, details, cgguts) <- hscNormalIface guts mb_old_iface
        hscInteractive (iface, details, cgguts) mod_summary
724
  }
725 726 727

-- Compile Haskell, extCore to bytecode.
hscCompileInteractive :: Compiler (InteractiveStatus, ModIface, ModDetails)
728
hscCompileInteractive = genericHscCompile hscInteractiveCompiler batchMsg
Thomas Schilling's avatar
Thomas Schilling committed
729

730 731 732
hscInteractiveBackendOnly :: TcGblEnv -> Compiler InteractiveResult
hscInteractiveBackendOnly = compilerBackend hscInteractiveCompiler

Thomas Schilling's avatar
Thomas Schilling committed
733 734
--------------------------------------------------------------

735
hscNothingCompiler :: HsCompiler NothingResult
dterei's avatar
dterei committed
736
hscNothingCompiler = HsCompiler {
737
    hscNoRecomp = \iface -> do
dterei's avatar
dterei committed
738 739
        details <- genModDetails iface
        return (HscNoRecomp, iface, details)
Simon Marlow's avatar
Simon Marlow committed
740

741
  , hscRecompile = genericHscRecompile hscNothingCompiler
742

743
  , hscBackend = \tc_result _mod_summary mb_old_iface -> do
dterei's avatar
dterei committed
744 745 746
        handleWarnings
        (iface, _changed, details) <- hscSimpleIface tc_result mb_old_iface
        return (HscRecomp Nothing (), iface, details)
747

748 749 750
  , hscGenBootOutput = \_ _ _ ->
        panic "hscCompileNothing: hscGenBootOutput should not be called"

751 752 753
  , hscGenOutput = \_ _ _ ->
        panic "hscCompileNothing: hscGenOutput should not be called"
  }
754

755
-- Type-check Haskell and .hs-boot only (no external core)
756
hscCompileNothing :: Compiler (HscStatus, ModIface, ModDetails)
757
hscCompileNothing = genericHscCompile hscNothingCompiler batchMsg
758

759 760 761
hscNothingBackendOnly :: TcGblEnv -> Compiler NothingResult
hscNothingBackendOnly = compilerBackend hscNothingCompiler

762 763 764 765
--------------------------------------------------------------
-- NoRecomp handlers
--------------------------------------------------------------

766 767 768
genModDetails :: ModIface -> Hsc ModDetails
genModDetails old_iface
  = do
dterei's avatar
dterei committed
769 770 771 772 773
    hsc_env <- getHscEnv
    new_details <- {-# SCC "tcRnIface" #-}
                   liftIO $ initIfaceCheck hsc_env (typecheckIface old_iface)
    liftIO $ dumpIfaceStats hsc_env
    return new_details
774

775 776 777 778
--------------------------------------------------------------
-- Progress displayers.
--------------------------------------------------------------

779
data RecompReason = RecompNotRequired | RecompRequired | RecompForcedByTH
dterei's avatar
dterei committed
780
    deriving Eq
781

782 783
oneShotMsg :: HscEnv -> Maybe (Int,Int) -> RecompReason -> ModSummary -> IO ()
oneShotMsg hsc_env _mb_mod_index recomp _mod_summary =
dterei's avatar
dterei committed
784 785
    case recomp of
        RecompNotRequired ->
786 787
            compilationProgressMsg (hsc_dflags hsc_env) $
                   "compilation IS NOT required"
dterei's avatar
dterei committed
788
        _other ->
789 790 791
            return ()

batchMsg :: HscEnv -> Maybe (Int,Int) -> RecompReason -> ModSummary -> IO ()
dterei's avatar
dterei committed
792 793 794 795 796 797 798 799 800 801 802 803 804
batchMsg hsc_env mb_mod_index recomp mod_summary =
    case recomp of
        RecompRequired -> showMsg "Compiling "
        RecompNotRequired
            | verbosity (hsc_dflags hsc_env) >= 2 -> showMsg "Skipping  "
            | otherwise -> return ()
        RecompForcedByTH -> showMsg "Compiling [TH] "
    where
        showMsg msg =
            compilationProgressMsg (hsc_dflags hsc_env) $
            (showModuleIndex mb_mod_index ++
            msg ++ showModMsg (hscTarget (hsc_dflags hsc_env))
                              (recomp == RecompRequired) mod_summary)
805

806 807 808
--------------------------------------------------------------
-- FrontEnds
--------------------------------------------------------------
809 810

hscFileFrontEnd :: ModSummary -> Hsc TcGblEnv
811
hscFileFrontEnd mod_summary = do
812
    hpm <- hscParse' mod_summary
813
    hsc_env <- getHscEnv
814
    dflags  <- getDynFlags
dterei's avatar
dterei committed
815 816 817
    tcg_env <-
        {-# SCC "Typecheck-Rename" #-}
        ioMsgMaybe $
818
            tcRnModule hsc_env (ms_hsc_src mod_summary) False hpm
819
    tcSafeOK <- liftIO $ readIORef (tcg_safeInfer tcg_env)
820 821

    -- end of the Safe Haskell line, how to respond to user?
822
    if not (safeHaskellOn dflags) || (safeInferOn dflags && not tcSafeOK)
823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838

        -- if safe haskell off or safe infer failed, wipe trust
        then wipeTrust tcg_env emptyBag

        -- module safe, throw warning if needed
        else do
            tcg_env' <- hscCheckSafeImports tcg_env
            safe <- liftIO $ hscGetSafeInf hsc_env
            when (safe && wopt Opt_WarnSafe dflags)
                 (logWarnings $ unitBag $
                     mkPlainWarnMsg (warnSafeOnLoc dflags) $ errSafe tcg_env')
            return tcg_env'
  where
    pprMod t  = ppr $ moduleName $ tcg_mod t
    errSafe t = text "Warning:" <+> quotes (pprMod t)
                   <+> text "has been infered as safe!"
839 840

--------------------------------------------------------------
841
-- Safe Haskell
842 843
--------------------------------------------------------------

844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863
-- Note [Safe Haskell Trust Check]
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- Safe Haskell checks that an import is trusted according to the following
-- rules for an import of module M that resides in Package P:
--
--   * If M is recorded as Safe and all its trust dependencies are OK
--     then M is considered safe.
--   * If M is recorded as Trustworthy and P is considered trusted and
--     all M's trust dependencies are OK then M is considered safe.
--
-- By trust dependencies we mean that the check is transitive. So if
-- a module M that is Safe relies on a module N that is trustworthy,
-- importing module M will first check (according to the second case)
-- that N is trusted before checking M is trusted.
--
-- This is a minimal description, so please refer to the user guide
-- for more details. The user guide is also considered the authoritative
-- source in this matter, not the comments or code.


864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894
-- Note [Safe Haskell Inference]
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- Safe Haskell does Safe inference on modules that don't have any specific
-- safe haskell mode flag. The basic aproach to this is:
--   * When deciding if we need to do a Safe language check, treat
--     an unmarked module as having -XSafe mode specified.
--   * For checks, don't throw errors but return them to the caller.
--   * Caller checks if there are errors:
--     * For modules explicitly marked -XSafe, we throw the errors.
--     * For unmarked modules (inference mode), we drop the errors
--       and mark the module as being Unsafe.


-- | Check that the safe imports of the module being compiled are valid.
-- If not we either issue a compilation error if the module is explicitly
-- using Safe Haskell, or mark the module as unsafe if we're in safe
-- inference mode.
hscCheckSafeImports :: TcGblEnv -> Hsc TcGblEnv
hscCheckSafeImports tcg_env = do
    hsc_env  <- getHscEnv
    dflags   <- getDynFlags
    tcg_env' <- checkSafeImports dflags hsc_env tcg_env
    case safeLanguageOn dflags of
        True -> do
            -- we nuke user written RULES in -XSafe
            logWarnings $ warns (tcg_rules tcg_env')
            return tcg_env' { tcg_rules = [] }
        False
              -- user defined RULES, so not safe or already unsafe
            | safeInferOn dflags && not (null $ tcg_rules tcg_env') ||
              safeHaskell dflags == Sf_None
895
            -> wipeTrust tcg_env' $ warns (tcg_rules tcg_env')
896

897
              -- trustworthy OR safe infered with no RULES
898 899 900
            | otherwise
            -> return tcg_env'

dterei's avatar
dterei committed
901 902 903 904 905 906
  where
    warns rules = listToBag $ map warnRules rules
    warnRules (L loc (HsRule n _ _ _ _ _ _)) =
        mkPlainWarnMsg loc $
            text "Rule \"" <> ftext n <> text "\" ignored" $+$
            text "User defined rules are disabled under Safe Haskell"
907

908 909 910 911 912
-- | Validate that safe imported modules are actually safe.
-- For modules in the HomePackage (the package the module we
-- are compiling in resides) this just involves checking its
-- trust type is 'Safe' or 'Trustworthy'. For modules that
-- reside in another package we also must check that the
913 914
-- external pacakge is trusted. See the Note [Safe Haskell
-- Trust Check] above for more information.
915
--
916 917 918 919 920 921
-- The code for this is quite tricky as the whole algorithm
-- is done in a few distinct phases in different parts of the
-- code base. See RnNames.rnImportDecl for where package trust
-- dependencies for a module are collected and unioned.
-- Specifically see the Note [RnNames . Tracking Trust Transitively]
-- and the Note [RnNames . Trust Own Package].